Diamond die and method of making same



Patented June 20, 1922:

f w w Y K A V 1- UNITED STATES] ABRAHAM SIMONS, OI NEW YORK, N. Y.

DIAl [OND DIE AND METHOD OF MAKING SAME.

Specification of Letters Patent. Patentgd June 20, 1922,

Application filed December 9, 1920. ,Serial No. 429,415.

T 0 all whom. it may concern:

Be it known that I, ABRAHAM SIMoNs, a citizen of Russia, residing at NewYork,

in the county of New York and State of New York, have invented certainnew and useful Improvements in Diamond Dies and Methods of Making Same,of which the following is a specification.

My invention relates to a new and 1mproved diamond die and a method ofmanufacturing the same.

Diamond dies have been heretofore largely used for the pur ose ofdrawing wire of great hardness. because of the necessity of usingdiamonds in them, and as heretofore made; the diamonds have often beenfractured by the great internal pressure which has been created by thedrawing of the wire. h

According to my invention, the diamond die is constructed in such amanner that a strong internal pressure, at right angles to the axis ofthe bore, is produced and thls internal pressure counterbalances theoutward disruptive force caused by the drawing of the wire.

This enables the use of a small diamond, since the diamond is reinforcedby the pressure of the surrounding metal.

Another object of my invention 1s to produce a diamond die in which thediamond 1s very firmly supported by the rigid metal enclosing it so thatany relative movement of the diamond is prevented as such movement nomatter how slight often produces the fracture thereof.

Other objects of my invention will be disclosed in the followingdescription and drawings which illustrate a preferred embodiment thereofFig. 1 is a sectional view and illustrates the'beginning of themanufacture of the dlamond plug.

Fig. 2 is also a vertical sectional view which illustrates the next stepin the manufacture of the die.

Fig. 3 is a vertical sectional view which hese dies are expensive lineof junction 9'.

invention, the diamond 1 is placed in ametal rod 2 having a recess 3which is closed by a tightly fitting plug 4.

The recess 3 may be filled with an inert gas such as nitrogen, beforethe plug 4 is inserted, but the amount of oxygen present in the recess 3is so slight that in practice it can be ignored.

As canbe seen in Fig. 1, the rod 2 is provided with a tapering conicalportion 5 and a long neck portion 6 extending therefrom 7 After the plug4 has been put into position, the rod 2 is heated adjacent the diamond 1until the metal thereof becomes hot and quite plastic.

The rod 2 is then forced into the opening of the die 7, which hasa-conical face 8 of a greater taper than the conical portion 5, and along internal recess 9 which corresponds in shape to the neck 6.

'Ordinarily, if the heating of the metal rod 2 before mentioned, is notvery carefully regulated, then the interiorof the recess 3 and theexterior of the diamond 1 become covered with films of oxide and eventhough these films are very thin, they'prevent the diamond from beingheld with sufficient tightness for the purpose for which it is intended,as this film or scale of oxide is of course very much weaker than themetal of the rod 2. However, by the use ofthe precautions abovementioned,*the formation of any film or scale prevented. y I

When the hot and plastic metal "of- 'the rod 2 has been forced undergreatipressure into the die7, the result can be seen in Fig. 2. As hereshown, the metal of'thje-n'eck 6 and of the conical portion 5 hascompletely closed over and surrounded the diamond 1, so that every partof the diamond 1 abuts against the metal of the rod 2, without anyintervening film of oxide, so-that the diamond is held with absoluterigidity and fir m. ness. As can be seen in Fig. 2, the metal above thediamond '1 is closed along the .ofoxide is. -absol utely 4 Thesuperfluous parts of the rod 2 are now is oppositely inclined to thetaper of the conical neck 5, so that the line of junction positionwithout using very much presure.

The holder 11 is now allowed to slowly cool and it exerts a heavypressure against the plug it) so as to very firmly compress the metalthereof against the diamond l. The plug 10 is made of as little width aspossible, so that the material thereof shall not interpose too muchresistance to the compression stresses caused by the cooling of theholder 11,.whereby the yielding of the material of the plug 10 causesthe said material to be firmly compressed against the diamond 1.

The diamond can be readily fractured by a sharp blow but it can resisttremendous internal streses if they are slowly and gradually applied andhence the internal pressure caused by the cooling of the holder 11 willnotfracture the diamond 1. A hole is now bored through the plug 10 andthe diamond 1, as shown in Fig. 4, and it will be noted that this borenow removes the metal adjacent the line of junction 9. The bore in thediamond 1 is substantially cylindrical in the middle thereof, and thenflares out at both ends, into substantially parabolic curves, theentering end. of the bore of the diamond being somewhat wider than theexit end as clearly shown in Fig. 4;. Experience has shown that thisparabolic contour is useful in ensuring the proper drawing of the wire.

The diamond is now subjected to powerful compression stresses in adirection substantially at right angles to the axis of the bore therein,and these compression stresses neutralize the outward disruptive forcepro duced when the wire is forced thrc To increase the compressioneffect roduced by the compressive. coolin the holder 11, this holder istapered adjacent the bore thereof, so that the periphery of the conicalplug 10 is subjected to the action of a longer mass of solidifyingmetal.

lit at any time the bore of the diamond becomes enlarged by the usethereof, the plug 10 can be readiiy forced out of the holder 11, becauseof the tapering contour thereof, and the diamond can be again utilized.

In the embodiment shown in Fig. 5, the plug is inserted into the holderwithout the use of heat to expand the holder.

As in the other embodiments, the exterior of the plug 10 and theinterior bore of the holder 11 are carefully ground so as to have thesame contour. The plug 10 is then placed into the bore 11 as shown inFig. 5, and the holder 11 is then placed in a hydraulic cylinder 12which is closed by means of a ca f 14 against which the holder 11 abuts.

he flexible washer 15 is placed around the lower or larger end of theplug 10.

The oil is then forced in under high pressure through the opening 16 andthis oil forces the plug 10 into position. As can be seen in Fig. 5, thewasher 15 only fits against the cylinder and the adjacent part of theholder 11. The pressure of the oil is uniform in all directions so theplug is forced in without any unbalanced internal stresses which wouldlead to the fracture of the diamond.

Of course, the amount of yield is very slight and it is to be understoodthat in actual practice, the exterior of the holder 11 will besufficiently spaced from the interior of the cylinder 12 to permit aslight outward yield thereof, although this is too small to be seen bythe naked eye.

I have shown a preferred embodiment of my invention, but it is clearthat numerous changes can be made in its details without departing fromits spirit.

I claim:

1. A diamond die embodying a bored diamond held in a body of contractedmetal and subjected to compressive stresses in a direction at an angleto the axis of the said bore.

2. A diamond die embodying a diam nd imbedded in a metal plug, the saiddiam nd and plug having a common bore therein. the said plug having aconical periphery and being seated in a holder having a bore of similarshape, the material of the said holder being compressed against the saidplug, so as to compress the material of the said ping against the saiddiamond.

3. A diamond die including a diamond firmly imbedded in a. contractedmetal plug, the said plug and diamond having a bore therein, theentering portion of the said common bore having curved elements whichhave a substantially parabolic contour.

in testimony whereof I hereunto afiix my signature.

. ABRAHAM SEMUNS.

